morphine/naltrexone (Embeda)

Introduction

Capsules containing extended-release morphine pellets with an inner core of the opioid antagonist naltrexone

Indications

• analgesia for patients at risk of substance abuse
• prevents one type of abuse, crushing the capsule to get all the morphine as immediate release

Dosage

• QD or BID dosing
• capsules can be opened & the pellets sprinkled on applesauce
• do NOT crush

Capsules:

• morphine 20 mg & naltrexone 0.8 mg
• morphine 30 mg & naltrexone 1.2 mg
• morphine 50 mg & naltrexone 2 mg
• morphine 60 mg & naltrexone 2.4 mg
• morphine 80 mg & naltrexone 3.2 mg
• morphine 100 mg & naltrexone 4 mg

Pharmacokinetics

• swallowing the capsules whole slowly releases just the morphine, but if the pellets are crushed, the naltrexone is released & can blunt morphine's effects

Adverse effects

• constipation (31%)
• nausea (22%)
• vomiting (8%)
• sleepiness (7%)
• headache (7%)
• itching (6%)
• dizziness (4%)
• fatigue (4%)

Drug interactions

• see morphine

• drug interaction(s) of morphine with ethanol

Notes

costs $250 to $850 for 60 caps (2009)

More general terms

• pharmacologic combination